Cannabis legalization in several jurisdictions has led to strong demand for products made from the oils and chemical compounds that can be extracted from Cannabis (referred to herein as “extracts”) and used by individuals without smoking the plant itself. For example, demand has grown in the areas of Pharmaceuticals commonly referred to as “medical marijuana,” and in nutritional supplements, edible products, and vaporizer fluids to name a few. Cannabis extracts are traditionally made by exposing cannabis plants to carbon dioxide, butane, propane, alcohol, glycerin, and/or other solvents in a vessel or mixer to leach the extracts from cannabis plants (a process referred to as leaching. Ultrasound also has been used in an attempt to liberate the extracts from the cannabis plant. These and other traditional techniques often suffer from issues such as low yield, high cost, safety issues, and/or contaminants that adversely affect the flavor or efficacy of the resulting extracts.
A need exists for a method of extracting CBD, THC, desirable oils, and other compounds from cannabis that addresses and resolves the problems and shortcomings of prior art leaching and other techniques, that is more efficient at extracting such compounds, that can be selective, and that does not introduce unwanted contaminants into the resulting extracts. There is a further need for a method and apparatus for maximizing the generally low extract yields that are characteristic of prior art extraction techniques. It is to the provision of such a method that the present invention is primarily directed.